Begin with:
lsof /var/lib/dpkg/lock
Then check if the process is running:
ps cax | grep PID
If the process is running, execute the following command (replacing PID with the output PID) to kill it:
kill -9 PID
Ensure that process is done:
ps cax | grep PID
Remove the lock file:
sudo rm /var/lib/dpkg/lock
Configure DPKG to continue with failed installation as a result of the lock
sudo dpkg --configure -a
Credit to Pooyan